For any government, bitcoin is like a type of foreign currency. Today non of the government (except Zimbabwe with a dysfunctional national monetary system) allow the circulation of foreign currency in domestic market
The reason that government don't care about bitcoin is because bitcoin's economy is still tiny, almost non-exist in the context of the national economy. But if bitcoin becomes widely spread and start to take significant part of the transaction in national economy, then there will be two currencies exist in the same economy. That will destroy all the exiting model of monetary theory and policy. I guess governments will all act like China and Russia, ban the use of it as currency
Then the payment function will become obsolete, leave it only with the function of international remittance and long term anti-inflation storage, which anyway is the main usage nowadays. Maybe that's a good thing, it means bitcoin does not need to handle several thousand transactions per second
I'm not sure that you are right about this.
Montenegro, after separation from Serbia, accepted Euro as official currency, even without official approval of EU.
So, they could also accept Bitcoin in the same way, as simple politic decision, if they could see and understand benefits of bitcoin as currency.
The time of great political change and major economic crisis is the right time for large and revolutionary changes if we have a government brave enough for such a decisions.
if I led the Greek government, and I'm under the threat of bankruptcy around the country, I'd be thinking about how to drop the euro and accept bitcoin.
I'm sure that such scenario will happen, soon or later and we will have first government to accept bitcoin as official currency.